Retrieve the Target of a URL suitable for sending in an HTTP Request

[madmongo1]

There is not ez-mode way to extract the HTTP Target from a url or url_view. I believe that this would be a common operation in real-world use. I think the library would benefit from a function to provide this.

Use case:

    boost::beast::websocket::response_type response;
    co_await ws.async_handshake(response, url.encoded_hostname(), target(url), use_awaitable);

My attempt at an implementation

/// Return the target form an HTTP URL suitable for specifying as the target in
/// an http request
std::string
target(boost::urls::url u)
{
    u.remove_scheme().remove_authority().remove_userinfo();
    if (!u.is_path_absolute())
        throw std::runtime_error(fmt::format("path not absolute: {}", u.string()));
    auto sv = u.string();
    return std::string(sv.begin(), sv.end());
}

[vinniefalco]

This seems HTTP-specific... I think it is the responsibility of the user

[madmongo1]

My unfounded assertion: This is going to be a huge source of support calls and user frustration. Users don't read RFCs. My compromise: show it as an example that users can copy/paste.

[vinniefalco]

We could offer

string_view
url_view_base::
encoded_target() const noexcept
{
    return get( id_path, id_frag );
}

[vinniefalco]

Try

urls::result< urls::url_view > = urls::parse_origin_form( s );

[alandefreitas]

The term target is kind of problematic because it can be more than origin_form.

request-target = origin-form
                    / absolute-form
                    / authority-form
                    / asterisk-form

and

urls::result< urls::url_view > = urls::parse_origin_form( s );

already exists.

[vinniefalco]

URI.js calls path+query+fragment the resource (we would call it encoded_resource). But this includes the fragment, which we don't want.

I think "target" is fine. "request-target" is not the same as "target." In fact target doesn't have any RFC meaning either in 3986 or 7230 so I think its okay. encoded_target for path+query, and encoded_resource for path+query+fragment.